How to Calculate the Optimal TV Screen Size Based on Resolution and Distance

Posted by Jim Tanous on September 1, 2016

When it comes to buying a new TV, most home theater enthusiasts naturally apply the “bigger equals better” philosophy. While this is often true, sometimes a bigger TV screen size won’t necessarily improve your home theater experience and, perhaps more importantly, spending more money on a bigger TV or 4K resolution could be a waste depending on the size of your room and the distance you plan to sit from the screen.

In short, if you sit too close to a large TV with a lower resolution, you risk seeing the screen’s individual pixels, which can ruin the movie-watching experience. Similarly, if you invest more money in a smaller 4K TV and sit too far away, you won’t be able to distinguish the extra pixels compared to the more affordable 1080p resolution.

The key factor in this balance between TV screen size, resolution, and viewing distance is called the angular resolution, the ability of your eye to distinguish small details in an object. The angular resolution varies between individuals based on each person’s unique eyesight but the same principle applies to everyone: after some point, everyone loses the ability to distinguish fine details once they’re a certain distance from the screen, and everyone can see individual pixels if they get too close.

TV Screen Size Calculator

Based on this information, some mathematical formulas can be derived which can guide you to the “optimal” TV screen size and resolution for a given viewing distance. Rather than force you to perform the calculations yourself, the folks over at Rtings.com have already crunched the numbers and offer a simple TV Size to Distance Calculator.

Rtings.com

Simply use the slider to set your viewing distance, select your resolution, and the calculator will present the optimal TV screen size for the given variables.

TV Screen Size Chart

Based on the aforementioned variability of human eyesight, however, you may be more interested in using the chart from which the calculator’s answers are derived. Unlike the calculator, the chart doesn’t offer an absolute answer to the perfect TV size, but rather presents a range at which a given size and resolution becomes “worth it.”

To use the chart, pick your anticipated viewing distance from the y-axis and then match it to a resolution and size on the x-axis. For example, if I wanted a UHD 4K TV but I sit 10-feet from the screen, I’d need to buy at least a 75-inch screen to be able to see the difference between 4K and 1080p.

On the other hand, if I wanted to save money and pick up a discounted 1080p TV, and I sit 6-feet from the screen, I shouldn’t buy anything larger than 45-inches if I want to ensure that I can’t see the set’s individual pixels.

Reverse the Numbers

Most people interested in this type of information are already working with a fixed room and are looking for the best TV to fit the space. If you’re working from scratch, however, such as planning a new home theater room, you can also use the calculator or chart to determine the optimal viewing distance for a given screen size. For example, if you’re dead set on getting a 65-inch 4K TV, you’ll want to sit about 6-feet from the screen (right in the middle of the 4K resolution range) for the best balance between having that big screen experience and not being able to see individual pixels. If you decide to stick with 1080p resolution, you’d need to sit about 8.5-feet away at the same 65-inch screen size.

The TV size and distance calculator and chart are great tools that can not only help you find the optimal size for the best viewing experience, but also help you avoid wasting money on pixels you may not be able to see. There are reasons other than resolution to upgrade to UHD, of course, but the Rtings.com tools are a great place to start. After all, as a friend once told me at the dawn of the HD transition, “it all looks like HD if you sit far enough away!”